[Android] Revert "Reset IME state on clear text input client" (#54277)

## Description

This PR reverts two commits #49829 and #53662.

The main change was in #49829. #53662 was a follow-up to mitigate the impact of #49829.

## Related Issue

Fixes flutter/flutter#148530
Fixes flutter/flutter#152620

Reopens flutter/flutter#70546.
Reopens flutter/flutter#51478

Author: bleroux

shell/platform/android/io/flutter/plugin/editing/TextInputPlugin.java

@@ -546,22 +546,11 @@ void clearTextInputClient() {
     }
     mEditable.removeEditingStateListener(this);
     notifyViewExited();
-
-    boolean needsRestart =
-        configuration.inputAction == null
-            || configuration.inputAction == EditorInfo.IME_ACTION_DONE
-            || configuration.inputAction == EditorInfo.IME_ACTION_NONE;
     configuration = null;
     updateAutofillConfigurationIfNeeded(null);
     inputTarget = new InputTarget(InputTarget.Type.NO_TARGET, 0);
     unlockPlatformViewInputConnection();
     lastClientRect = null;
-
-    if (needsRestart) {
-      // Call restartInput to reset IME internal states. Otherwise some IMEs (Gboard for instance)
-      // keep reacting based on the previous input configuration until a new configuration is set.
-      mImm.restartInput(mView);
-    }
   }
 
   private static class InputTarget {

shell/platform/android/test/io/flutter/plugin/editing/TextInputPluginTest.java

@@ -1130,150 +1130,6 @@ public void setTextInputEditingState_nullInputMethodSubtype() {
     assertEquals(1, testImm.getRestartCount(testView));
   }
 
-  @Test
-  public void clearTextInputClient_restartsImmWhenInputActionIsNull() {
-    // Initialize a general TextInputPlugin.
-    InputMethodSubtype inputMethodSubtype = mock(InputMethodSubtype.class);
-    TestImm testImm = Shadow.extract(ctx.getSystemService(Context.INPUT_METHOD_SERVICE));
-    testImm.setCurrentInputMethodSubtype(inputMethodSubtype);
-    View testView = new View(ctx);
-    TextInputChannel textInputChannel = new TextInputChannel(mock(DartExecutor.class));
-    TextInputPlugin textInputPlugin =
-        new TextInputPlugin(testView, textInputChannel, mock(PlatformViewsController.class));
-    textInputPlugin.setTextInputClient(
-        0,
-        new TextInputChannel.Configuration(
-            false,
-            false,
-            true,
-            true,
-            false,
-            TextInputChannel.TextCapitalization.NONE,
-            null,
-            null,
-            null,
-            null,
-            null,
-            null));
-    // There's a pending restart since we initialized the text input client. Flush that now.
-    textInputPlugin.setTextInputEditingState(
-        testView, new TextInputChannel.TextEditState("", 0, 0, -1, -1));
-    assertEquals(1, testImm.getRestartCount(testView));
-
-    // A restart is always forced when calling clearTextInputClient().
-    textInputPlugin.clearTextInputClient();
-    assertEquals(2, testImm.getRestartCount(testView));
-  }
-
-  @Test
-  public void clearTextInputClient_restartsImmWhenInputActionIsDone() {
-    // Initialize a general TextInputPlugin.
-    InputMethodSubtype inputMethodSubtype = mock(InputMethodSubtype.class);
-    TestImm testImm = Shadow.extract(ctx.getSystemService(Context.INPUT_METHOD_SERVICE));
-    testImm.setCurrentInputMethodSubtype(inputMethodSubtype);
-    View testView = new View(ctx);
-    TextInputChannel textInputChannel = new TextInputChannel(mock(DartExecutor.class));
-    TextInputPlugin textInputPlugin =
-        new TextInputPlugin(testView, textInputChannel, mock(PlatformViewsController.class));
-    textInputPlugin.setTextInputClient(
-        0,
-        new TextInputChannel.Configuration(
-            false,
-            false,
-            true,
-            true,
-            false,
-            TextInputChannel.TextCapitalization.NONE,
-            null,
-            EditorInfo.IME_ACTION_DONE,
-            null,
-            null,
-            null,
-            null));
-    // There's a pending restart since we initialized the text input client. Flush that now.
-    textInputPlugin.setTextInputEditingState(
-        testView, new TextInputChannel.TextEditState("", 0, 0, -1, -1));
-    assertEquals(1, testImm.getRestartCount(testView));
-
-    // A restart should be forced when calling clearTextInputClient() and input action is
-    // EditorInfo.IME_ACTION_DONE.
-    textInputPlugin.clearTextInputClient();
-    assertEquals(2, testImm.getRestartCount(testView));
-  }
-
-  @Test
-  public void clearTextInputClient_restartsImmWhenInputActionIsNone() {
-    // Initialize a general TextInputPlugin.
-    InputMethodSubtype inputMethodSubtype = mock(InputMethodSubtype.class);
-    TestImm testImm = Shadow.extract(ctx.getSystemService(Context.INPUT_METHOD_SERVICE));
-    testImm.setCurrentInputMethodSubtype(inputMethodSubtype);
-    View testView = new View(ctx);
-    TextInputChannel textInputChannel = new TextInputChannel(mock(DartExecutor.class));
-    TextInputPlugin textInputPlugin =
-        new TextInputPlugin(testView, textInputChannel, mock(PlatformViewsController.class));
-    textInputPlugin.setTextInputClient(
-        0,
-        new TextInputChannel.Configuration(
-            false,
-            false,
-            true,
-            true,
-            false,
-            TextInputChannel.TextCapitalization.NONE,
-            null,
-            EditorInfo.IME_ACTION_NONE,
-            null,
-            null,
-            null,
-            null));
-    // There's a pending restart since we initialized the text input client. Flush that now.
-    textInputPlugin.setTextInputEditingState(
-        testView, new TextInputChannel.TextEditState("", 0, 0, -1, -1));
-    assertEquals(1, testImm.getRestartCount(testView));
-
-    // A restart should be forced when calling clearTextInputClient() and input action is
-    // EditorInfo.IME_ACTION_NONE.
-    textInputPlugin.clearTextInputClient();
-    assertEquals(2, testImm.getRestartCount(testView));
-  }
-
-  @Test
-  public void clearTextInputClient_doesNotRestartImmWhenInputActionIsNext() {
-    // Regression test for https://github.com/flutter/flutter/issues/148673.
-    // Initialize a general TextInputPlugin.
-    InputMethodSubtype inputMethodSubtype = mock(InputMethodSubtype.class);
-    TestImm testImm = Shadow.extract(ctx.getSystemService(Context.INPUT_METHOD_SERVICE));
-    testImm.setCurrentInputMethodSubtype(inputMethodSubtype);
-    View testView = new View(ctx);
-    TextInputChannel textInputChannel = new TextInputChannel(mock(DartExecutor.class));
-    TextInputPlugin textInputPlugin =
-        new TextInputPlugin(testView, textInputChannel, mock(PlatformViewsController.class));
-    textInputPlugin.setTextInputClient(
-        0,
-        new TextInputChannel.Configuration(
-            false,
-            false,
-            true,
-            true,
-            false,
-            TextInputChannel.TextCapitalization.NONE,
-            null,
-            EditorInfo.IME_ACTION_NEXT,
-            null,
-            null,
-            null,
-            null));
-    // There's a pending restart since we initialized the text input client. Flush that now.
-    textInputPlugin.setTextInputEditingState(
-        testView, new TextInputChannel.TextEditState("", 0, 0, -1, -1));
-    assertEquals(1, testImm.getRestartCount(testView));
-
-    // No restart is forced when calling clearTextInputClient() and input action is
-    // EditorInfo.IME_ACTION_NEXT.
-    textInputPlugin.clearTextInputClient();
-    assertEquals(1, testImm.getRestartCount(testView));
-  }
-
   @Test
   public void destroy_clearTextInputMethodHandler() {
     View testView = new View(ctx);